The hazards to the general public and medical staff due to needle sticks from used syringes, as well as the problems associated with re-use of syringes by intravenous drug users is well documented. Many prior attempts have been made to provide a syringe which is capable of only a single use and which, after such use is self destructing or provides protection against needle sticks. One such syringe is disclosed in U.S. Pat. No. 5,267,976 for example. Generally speaking the prior art devices suffer one or more disadvantages in that they are too costly to manufacture, are unreliable, are easily tampered with or rely on the user taking some positive action after first use, to ensure that the syringe is disabled from further use. In prior art devices which have an automatically retracting needle such as that disclosed in aforementioned U.S. Pat. No. 5,267,976 there is also the possibility of premature retraction of the needle such as when the plunger is moved from its packaged position in preparation for drawing a drug into the syringe.